The data protected by the perfect secrecy system are unable to be cracked no matter how many ciphertexts cryptanalysts intercept, in the infinite computing power and time conditions, and the specific content refers to the document Shannon, Claude (1949). Communication Theory of Secrecy Systems, Bell System Technical Journal 28 (4): 656-715.
The one-time-pad (hereinafter referred to as OTP) is one of the typical implementations, and the relevant content can refer to the following documents, U.S. Pat. No. 1,310,719. SECRET SIGNALING SYSTEM, S N Molotkov, “Quantum cryptography and V A Kotel'nikov's one-time key and sampling theorems”, PHYS-USP, 2006, 49 (7), 750-761 and Pages 6 and 12 of Applied Cryptography issued by the Machinery Industry Press on Mar. 1, 2003.
At present, the perfect secrecy system is achieved mainly based on the key, namely, how each bit of the plaintext is encrypted by an infinite number of true random keys to achieve the design purpose of the perfect secrecy system. However, the encryption algorithm used is mostly a single XOR, or other, the security of the whole system is totally dependent on the secure storage and transmission of the keys. Once the keys are disclosed, the security of the whole system is very fragile.